There she goes! That woman (could be any one of us) walking down the street pushing a buggy. She's exhausted, several sizes over her fighting weight wearing zero-effort saggy bottom trousers and undersized top. She has succumbed to nappy limbo but for one crucial detail - her sunglasses. Big, challenging, glamorous, shout-out loud shades in coal black wrap-around sides, these six inches of moulded plastic do a job no other item of clothing could do - they give back her edge despite the baby-sick down her shoulder.
The stick thin guy pushing his bike down hill has invested in the latest circulation restricting lycra shorts – an object of mirth? Perhaps if not for those super cool mirrored sporty logo’d must haves – and suddenly he is Bradley Wiggins.
The beauty of sunglasses is that there is no age after which you can't wear them. They can't be slutty or mutton dressed up as lamb. You can afford to take the plunge into the designer deep end with prices starting as low as £35 or for the technically minded there are no end of innovations available not only in lens development but the frames too. These days you can get spectacle frames with in- built video cameras, smart phones and heads up displays.
Even when they are not a defining part of the look, sunglasses give you an instant injection of attitude and glamour. If you have a hangover or swollen eyes, or just if you don't much fancy being exposed to the world, there is no more effective barrier. You can be bored, weary or injured by a mascara wand and no-one will be the wiser.
But let’s get closer to the real subject of my heart Sunglass Lenses!
Pink, green, purple or satanic black. £1 off the market or £300 from the sunglass boutiques – what is the difference? Well lets look in more detail…….
What is this UV stuff People Talk About?
Ultraviolet light (UV) is just another part of the colour spectrum, we can see the red, orange, yellow, green, blue, indigo and violet but we can’t see the ultra violet with our human eyes.
It is the UV light that does so much damage to our unprotected skin and eyes. Some people think about sun protection only when they spend a day in the sun at the beach but sun exposure adds up day after day every time you are in the sun.
We all know the consequences to skin damage : painful sunburn, skin cancer, wrinkles, sags and bags. This same damaging light is entering our lovely clear, translucent corneas so what havoc is it wreaking inside? The answer is scary : potential problems are cataract, macular degeneration (most common cause of blindness in the UK), pterygium – a growth on the white of the eye that can involve the cornea, and keratitis (corneal sunburn) – very painful.
It is just so very odd that we are pretty careful about slapping on the sunscreen to our poor pink peeling bodies but think nothing about wandering around with just our ordinary spectacles or nothing at all to cherish our wonderful eyes! And so important for children and babies! What are we doing allowing them out of the house without the vital protection they need at such a vulnerable age?
What should I do to protect my eyes?
UV rays reach the ground all year, even on cloudy days but the strength of the rays are most intense in the Spring before temperatures get warmer. You need to be careful on the beach or in areas with snow because sand, water and snow reflect sunlight increasing the amount of UV radiation.
Some UV rays can also pass through windows but don’t pose a great deal of risk unless you spend long periods of time close to the glass that gets direct sunlight – for example lorry drivers.
There is no sunscreen for eyes so we have to rely on sunglasses to give us the protection we need.
Read the Labels
The ideal sunglasses should block 99% to 100% UVA and UVB rays. Before you buy, check the label to make sure they do. Labels that say “UV absorption up to 400nm” mean the glasses block at least 99%. Those labeled “cosmetic” do not and if there is no label, don’t assume they provide any protection at all.
Darker does not mean better because the protective stuff in the lens is not the coloured part. Large framed and wrap around sunglasses are more likely to protect your eyes from light coming in from different angles. Children need smaller versions of real adult spectacles - not toy sunglasses.
What Sort of Lenses are Best?
There are several types of lenses and they all have their good and bad points so it becomes a matter of personal preference once you are reassured that they all offer the UV protection you need.
The most common option for many spectacle wearers is to have photochromatic lenses which go dark in sunlight and lighten when indoors. This is an economic way to protect the eyes all year round as you don’t need another separate pair for the bright days and they are always to hand. The tinting levels vary so they are always at a suitable level no matter what the weather. The downside to these lenses are that you are likely to be wearing some very dark lenses on those days that are quite cloudy maybe even wintery – this is not a bad thing for your eyes but not everyone wants to have dark lenses in Winter. Some people find that although quick to go dark they are slower to clear and the elderly struggle more with this aspect of the lenses than younger subjects. Their performance behind glass is less impressive and although they darken they do not do so to their full potential and this makes them perform poorly for the car driver.
These lenses come in options of brown, grey or green with a further option for a brand called Xtractive which does perform better behind the car windscreen.
Any uncoated spectacle lens can be tinted to virtually any colour and to what ever depth of tint you choose and this allows plenty of artistic license to have stripes, checks, two tones, graduated tones in purples, blues, pinks or green and there is a great range of tinted lenses available off the shelf too. The most important part though is that those lenses have a UV block added because the colouring will not do anything to block the damaging light. The only way to ensure that this critical coat is on the lens is to purchase from reputable retailers because there are so many imported sunglasses that would not pass any quality control testing so buyer beware!
These are filters that are incorporated into the lens material at manufacture and are not added as an extra process. These filters are often used for very specialized situations ie migraine control, people with blue light sensitivity and certain clinical conditions.
However there are some manufacturers such as Rayban who incorporate these tints into their main sunwear range. The advantage of these tints is that they are deliberately targeted at controlling those wavelengths of light that give us the most bother (mainly blue) and the colour will not fade. These tints would not be suitable for wearers of thicker prescriptions as the colour would be darkest in the thickest parts of the lens. Many of these solid tints are often glass and should be worn with caution by the vulnerable or sporty for obvious safety reasons.
The polarizing lens is the most comfortable lens to wear as it is the only lens to eliminate blinding glare.
Light waves will travel in all directions and the human eye views vertical light waves clearly. Horizontal light, particularly the concentrated light reflecting off a horizontal shiny surface such as a car bonnet, water, snow or asphalt roads will be perceived as glare. Glare reduces visibility and can often be very uncomfortable even dangerous when the intensity is very high. We have all experienced the scenario of driving into sunlight after a heavy rainfall- it can sometimes be so bad that it is almost impossible to see ahead safely.
Non-polarized lenses offer a general filter to the light so that the overall effect is that of dampening the glare. However, each element of the light wave is diminished too so this will also have a knock-on effect to our visual acuity (quality or sharpness of vision).
Polarizing lenses will let in the vertical light just like an upright letterbox allowing us to retain clear vision but keeps out the glare inducing remainder. In this way when we are near water the polarizing lens comes into its own as it allows us to clearly see the fish and rocks below the surface.
A polarizing lens will improve visual comfort, reduce eyestrain, improve contrast and visual acuity, reduce reflection and eliminate glare whilst allowing for true perception of colours.
With all lenses there are downsides and there some issues with polarizing lenses: they are not recommended for motorbike riders because it is not possible to see oil or ice patches on the road and this will also apply to skiers who won’t be able to see the normally shinier patches of ice. Liquid crystal displays are not readable and so this would affect viewing of a motorbike’s instrumentation or that of an aircraft.
Do be aware that not all polarizing filters are effective – some very cheap ones will only cut out a small proportion of the light compared to the very good quality brands available – again please get your protective eyewear from reputable retailers who are able to discuss knowledgeably about your visual requirements. Registered Opticians and Optometrists are extremely educated regarding sun-protection, as this is part of several years of under-graduate and then continuing post-graduate education, do seek their advice.